Carhartt® Our heavyweht zip-fro sweatshirt is now available in flame-resistant fabric. Made of heavyweight flame-resistant 14-ounce knit, 58% cotton/35% modacrylic/7% polyester, it features an attached hood and FR draw cord closure and two front handwarmer pockets. A Carhartt FR and HRC 3 labels are sewn on the left-front pocket.